1. Field of the Invention
The present invention relates to a method for inhibiting the synthesis of methamphetamine via the reduction of ephedrine (also known as (−)ephedrine, 1-ephedrine, [1R,2S]-(−)-2-methylamino)-1-phenylpropan-1-ol), or its stereoisomer pseudoephedrine (also known as (+)-P-ephedrine, d-isoephedrine, d-pseudoephedrine, [1S,2S]-(+)-2-[methylamino]-1-phenylpropan-1-ol)). More particularly, this invention relates to the introduction of a chemical reagent into anhydrous ammonia, a common solvent used in the illicit synthesis of methamphetamine (also known as (S)-N,α-dimethylbenzene-ethanamine, (S)-(+)-N,α-dimethylphenethylamine, d-N-methylamphetamine, d-deoxyephedrine, d-desoxyephedrine, 1-phenyl-2-methylaminopropane, d-phenylisopropylmethylamine, methyl-β-phenylisopropylamine, and Norodin), so as to inhibit and/or prevent the use of the ammonia in the reduction of ephedrine/pseudoephedrine to methamphetamine.
2. Description of the Related Art
Of all the drugs of abuse, methamphetamine is the only one so simple to prepare that the individual user can make it independently. It is estimated that 99% of the clandestine laboratories in the United States are involved in the illicit manufacture of methamphetamine. An increasing number of the clandestine methamphetamine laboratories (currently roughly estimated at 20%) use a procedure known as a dissolving metal reduction, Birch reduction, or in the popular literature as the “Nazi” method, of ephedrine or pseudoephedrine commonly extracted from over-the-counter medications. The details for the synthesis are readily available from the open literature and the Internet. Unlike other synthetic drugs, less than 10% of those arrested for the illicit synthesis of methamphetamine are trained chemists.
The relative ease with which methamphetamine is manufactured has led to a proliferation of small-scale “mom and pop” operations. The small-scale labs produce only a small amount of the methamphetamine available in this country. However, clandestine laboratories, often operated by criminally minded individuals untrained in the handling of dangerous chemicals, pose threats of fire, explosion, poison gas, booby traps, and the illegal dumping of hazardous waste. The solvent of choice used for the Nazi synthesis is anhydrous ammonia, often obtained by theft from farmers' supply tanks. The thieves normally pilfer only a few gallons of anhydrous ammonia but too often are the cause of major ammonia spills. Such spills have not only resulted in the loss of thousands of gallons of ammonia for individual farmers, but have resulted in the evacuations of entire towns due to the toxic cloud of ammonia produced.
The handling of anhydrous ammonia is an extraordinarily dangerous activity. The liquid is extremely cold (boiling point, −28° F.) and the vapor is highly volatile. Contact of the liquid with skin or mucus membranes causes a combination of frostbite, direct ammonolysis of the skin by ammonia, and saponification of the epidermal fats by ammonium hydroxide formed by the reaction of ammonia and water. A very real concern is severe injury to children who learn about methamphetamine synthesis from the Internet without knowledge of the risks associated with the handling of anhydrous ammonia.
The small-scale clandestine laboratories are often considered to be more dangerous than the larger scale labs. Smaller scale laboratories suffer from amateur chemists inexperienced in the handling of hazardous chemicals and the consequences of potential accidents. This point is evident from the large number of children present at clandestine laboratories seized in 1999, nearly 870 children were reported to be at the sites with 180 exposed to toxic chemicals and 12 found injured by the chemicals.
The small size of the clandestine methamphetamine labs and the brief time required for the methamphetamine synthesis provide stealth for the laboratories. The required equipment will easily fit into the trunk of a car. The methamphetamine synthesis can be carried out in a hotel room or on the side of the road before disposing of the waste and concealing the laboratory equipment. The Nazi method enjoys the advantage of producing relatively little odor compared with other synthetic methods, greatly minimizing the risk of detection.
The key reagent in the Nazi methamphetamine synthesis is the solvated electron. The solvated electron is a potent reducing agent and is sufficiently long-lived in liquid ammonia that it is useful for synthetic purposes. Dissolving metal reagents, typically alkali and alkaline earth metals, in anhydrous ammonia generates the solvated electron, as follows, using lithium as an example:       Li    ⁢          ⟶              NH        3              ⁢                  Li        ⁡                  (                      NH            3                    )                    n      +        +                    e        ⁡                  (                      NH            3                    )                    m      -        .  where Li is lithium metal, NH3 is the ammonia solvent, and Li(NH3)n+ and e(NH3)m− are the ammonia solvated lithium ion and electron, respectively. The proposed mechanism of the dissolving metal reduction reaction involves the two-electron reduction of ephedrine or pseudoephedrine to give the methamphetamine product, as follows: where the chirality of the carbon center alpha to the phenyl ring is lost during the reduction.
It is an object of the present invention to increase the level of difficulty, time, equipment, and supplies necessary to synthesize methamphetamine by the dissolving metal reduction method. Because the average methamphetamine producer has relatively low chemistry skills, increasing the level of difficulty is expected to significantly decrease the number of individuals capable of conducting the procedure. Additionally, by increasing the time, equipment, and supplies required for the synthesis, the risk of detection of the clandestine laboratory will increase as well.
It is a further object of the invention to provide a method of preventing methamphetamine synthesis from anhydrous ammonia whereby electrons present in the ammonia will react with a chemical reagent in preference over ephedrine and/or pseudoephedrine. By this method, the reagent will interfere with, or eliminate, the ability of electrons to reduce ephedrine and/or pseudoephedrine to methamphetamine.
It is an object of the invention therefore to identify chemical reagents which will react with solvated electrons more efficiently than ephedrine and/or pseudo ephedrine.